Boston Municipal Court Judge Raymond G. Dougan has told several associates that he is facing a new investigation by the agency that oversees Massachusetts judges, just weeks after the agency cleared him of being biased in ­favor of criminal defendants.

The Commission on Judicial Conduct does not confirm its ­investigations, but Dougan has told several people in the court system that the agency is investigating a report that he violated ethical standards by accepting at least $85,000 in free legal services from the law firm that defended him during the two-year bias inves­tigation.

Court officials tell the Globe that Dougan has been complaining about the new inquiry.

Dougan and his lead lawyer, Michael B. Keating, declined to comment, but the former longtime executive director of the ­Judicial Conduct Commission said the rules are clear: Judges cannot have lawyers representing them for free before the agency to avoid even the appearance of ­impropriety.

“As far as I am aware, in the 24½ years that I worked for the Commission on Judicial Conduct, every judge who had a lawyer representing him or her before the commission paid that lawyer’s full fee,” said Gillian Pearson, who served as executive director of the commission until she retired last summer.

“If I had become aware of any instance where that was not true, I would have immediately taken action” to notify the judge that he or she should not receive free services, she said.

Although Dougan disclosed that he was receiving pro bono legal help in required annual reports to the State Ethics Commission and the Supreme Judicial Court, he did not directly inform the Judicial Conduct Commission. As a result, the agency learned of the arrangement when the Globe reported it last month.

The investigation of Dougan has caused an enormous stir in Boston legal circles, beginning with the unusual 61-page complaint brought by Suffolk District Attorney Daniel F. Conley, which argued that Dougan habitually rules in favor of criminal defendants even when evidence of their guilt is extensive.

Dougan, first justice of the court that handles criminal cases in most of downtown ­Boston, has long clashed with prosecutors over everything from setting defendants’ bail to the appropriate sentence after conviction. A Globe review of court records shows that prosecutors appeal Dougan’s decisions more often than any other Boston judge, and Conley’s ­office routinely asks Dougan to step down from cases on the grounds he cannot be fair.

But defense lawyers rallied to Dougan, accusing the district attorney of bullying an independent-­minded judge. Keating, a partner in the prominent law firm Foley Hoag, agreed in late 2010 to defend Dougan for nothing, arguing that the bias complaint threatened the whole idea of judicial independence.

Keating and two other Foley Hoag lawyers defended Dougan all the way to the state’s highest court, convincing the SJC that Dougan should not have to ­answer investigators’ questions about what he was thinking when he made particular decisions. The landmark ruling also bars future investigators from probing judges’ thought process.

Finally, on Nov. 30, the chairman of the Judicial Conduct Commission wrote a letter to Dougan saying that the panel had dismissed Conley’s bias complaint against him after review­ing a 1,000-page report on Dougan’s record compiled by an independent counsel, J. William Codinha

That might have been the end of the controversy, except for Dougan’s financial disclosures showing he had received a large amount of free legal services. He told the SJC that Foley Hoag donated $15,000 worth of services to him in 2010, and he told the State Ethics Commission that the firm gave him “more than 100 hours” of work in 2011, work that would typically cost at least $70,000.

Dougan has not yet disclosed the amount of free legal services he received in 2012, but legal observers say the final value of the gift could easily top $100,000, perhaps by a lot.

The rules of judicial conduct prohibit judges from receiving gifts from law firms whose lawyers have appeared before them or are likely to in the future. State ethics law also bars public officials from accepting most gifts if they are given because of the job the official holds.

Keating has argued that representing Dougan for free violated no ethical rules because neither he nor the two other lawyers who worked on the case have ever appeared before Dougan specifically. Foley Hoag lawyers seldom appear in district courts except for cases handled by their large pro bono department, which often represents victims of domestic abuse.

However, a review of Boston Municipal Court records turned up at least one case in which a Foley Hoag lawyer did appear in Dougan’s court.

In that 2001 case, the Foley Hoag lawyer represented a man accused of threatening and ­harassing a former girlfriend, who sought an abuse prevention order. Dougan sided with the defendant and refused to ­issue the order.

Keating, who is chairman of his firm’s litigation department and a former head of the ­Boston Bar Association, said his firm does not expect anything in return for the legal services he provided to Dougan. He said Foley Hoag accepted the case pro bono because it raised an important principle.

“The case concerned an ­issue vital to the effective functioning of the judiciary, ensuring that judges are able to make decisions free from the threat of excessive intrusion,” Foley Hoag wrote in a recent letter to ­Lawyers Weekly.

But, during the Dougan inves­tigation, Keating declined to reveal who was paying the judge’s legal costs. Asked directly about the legal bills by a report­er in early 2011, Keating said, “I can’t comment on that.”

Keating would not estimate the value of the law firm’s services to Dougan or say what his usual fee is. Experts said the city’s top lawyers bill $700 an hour and up.

Keating also declined to comment on whether the Judicial Conduct Commission has launched a new inquiry into the free legal services he provided to Dougan.

“It would be inappropriate for me to comment on the matters referred to in your e-mail. All matters pertaining to the Commission on Judicial Conduct, including the existence or nonexistence of a complaint, are confidential,” Keating wrote in an e-mail.

Dougan also declined to comment, but several people inside the court system told the Globe that Dougan had confirmed the investigation to others, complaining that he had ­already endured a two-year ­review. All asked not to be identified out of fear of jeopardizing their relationship with Dougan.

If the commission substantiates a complaint against ­Dougan, the agency can impose sanctions. If the judge agrees, those penalties can include counseling, admonishment, private reprimand, or voluntary retirement.

If the judge does not agree, the commission must decide whether to bring formal charges. If so, the SJC would appoint a hearing officer to issue recommendations and would decide the appropriate punishment, if any.

No judge can be removed from office in Massachusetts.

The State Ethics Commission could also investigate the gifts. If it found Dougan violated the law, it could fine him up to $10,000 for each violation and require him to pay the legal bills.

Possible outcomes

If the commission substantiates a complaint against Dougan, the agency can impose sanctions.

If the judge agrees, those penalties can include counseling, admonishment, private reprimand, or voluntary retirement.

If the judge does not agree, the commission must decide whether to bring formal charges.

If so, the SJC would appoint a hearing officer to issue recommendations and would decide the appropriate punishment, if any.